The present invention is directed to apparatus for cleaning the compressor blades of a turbine and particularly relates to apparatus for robotic washing of the compressor blading of a plurality of compressor stages by accessing the blading through the compressor inlet and without disassembly of the compressor casings or removal of the compressor rotor.
Turbines, for example, gas turbines, undergo changes in performance over time. Fundamentally, losses in the compressor and turbine are caused by a deterioration of blade and casing surface finishes, blade shape profile changes, rubs and other flow path distortions. Power and efficiency are reduced as a result of these frictional and aerodynamic changes. The majority of the aggregate losses are attributable to the compressor.
Turbine performance can be recovered to varying degrees by compressor washing processes designed to remove fouling and-deposition on the compressor blading. Current practices include water-washing the compressor blading in either an online or offline configuration. For example, an online wash is the process of injecting water into the compressor while the turbine is running at full speed and some percentage of load. Offline washing is the process of injecting a cleaning solution into the compressor while it is being turned at cranking speed. While these processes are generally effective, there are still residual losses after cleaning. For example, the advantage of the offline cleaning process is its ability to break down less water-soluble, oily deposits, but neither process restores compressor performance to the level of a hand-scour, which can be attained only during a major outage and disassembly of the compressor. Consequently, at present, these residual losses are addressed only by removal of casings and aggressive restoration work or parts replacement, all of which are costly. Accordingly, there is a need for a more effective cleaning process which would substantially restore the efficiency of the compressor blading to nearly its original efficiency during outages but without disassembly of the turbine in order to maximize recovery of turbine losses over time and provide the equivalent extension of part lives.